Generally, while vacuum cleaners provide convenience in their use, they produce a lot of noise, and therefore, there is the problem that an interior of a room becomes very noisy during their use.
The reason why the conventional vacuum cleaners are very noisy is that they are not equipped with effective noise shielding means, noise absorbing means and vibration absorbing means, as shown in a structure of FIG. 9.
In a conventional vacuum cleaner, which is illustrated in FIG. 9, the noise from an electric blower 1, which is the noise generating source is shielded only once, and most of the noise is propagated to outside by passing through a body of the vacuum cleaner.
Further, the noise is transmitted through an outlet section 32 to the outside without being hindered by anything at all, and further, the noise is also transmitted to the outside by passing through an air suction hole 37 which is formed on a partition wall 36 which isolates a dust collecting room X and a blower receiving room Y from each other.
Further, vibrations are generated upon activating the electric blower, but there is nothing provided to absorb these vibrations.
The usual conventional vacuum cleaners as described above are very inconvenient because of the severeness of the noise they produce, and therefore, users are waiting for a vacuum cleaner which produces little or no noise.
Japanese Patent Publication No. Sho-63-25775 which was published on May 26, 1988 after being filed by Sharp Corporation of Japan on Apr. 8, 1982 is constituted such that the discharge path of filtered air is curvedly formed, and that noise shielding means and noise absorbing means are provided.
In the vacuum cleaner of the prior art as mentioned above, discharge path is curved in such a way that filtered air which is discharged backwardly from a rear portion of the electric blower is allowed to collide with the body of the vacuum cleaner, and then, is allowed to turn toward a front. However, the technology that the filtered air passing through the discharge path is protected from being subject to resistance has not been developed. Further, the noise shielding means and the noise absorbing means are installed only around the electric blower.
Thus the improved vacuum cleaner of the prior art is capable of reducing the noise to a certain degree, but not to the extent that users are satisfied.
Vacuum cleaners have to have strong suction power in order to suck up dust and dirt, and therefore, it is generally recognized that a noisy vacuum cleaner has to be accepted, with further reduction of noise being impossible.